JP2000062191A - Method and apparatus for manufacturing ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-quality recording in which a large number of electrodes having good uniformity and little variation can be provided with an electrode having a metal thin film formed on an insulating resin protruding from an end surface of a head substrate. The present invention provides an ink jet recording apparatus and a method for manufacturing the same, which enables the above. SOLUTION: A resin film is formed on an insulating substrate having a concave groove, an electrode pattern and a guide member pattern are formed on the upper portion of the groove, and dry etching is performed to protrude from an end of the substrate to form a resin film on the resin film. The formed thin film electrode and the guide member installed adjacent thereto can be formed. These are methods that can be formed only by a semiconductor processing process, and can easily and inexpensively manufacture a high-density, high-resolution line head having a large number of electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention aggregates a coloring agent component in an ink in which a coloring agent is dispersed in a solvent by electrostatic force,
The present invention relates to a method for manufacturing an inkjet recording head and an inkjet recording apparatus for flying a recording medium to perform recording.

[0002]

2. Description of the Related Art In recent years, with the spread of personal computers, ink jet printers using an ink jet recording system have been widely used. Inkjet printers are characterized by non-contact with recording media because ink is ejected for printing, noise is low, and there is no need for complicated mechanisms such as development and fixing as in electrophotographic printers. High quality color recording is possible.

There are various types of ink jet printers, and a typical one is a thermal ink jet type in which bubbles are instantaneously generated by a heating resistance element and ink is ejected by the pressure of the bubbles, or a piezoelectric element is used. There is a piezo method that converts electrical signals into mechanical vibrations to eject ink. In each of these inkjet printers, since ink is ejected through the nozzles, it is difficult to increase the number of nozzles in a line head or the like due to problems such as nozzle clogging.

On the other hand, in Japanese Unexamined Patent Publication No. 62-5282, an ink in which a charging colorant component (toner) is dispersed in an insulating solvent is introduced into an opening provided with an electrode, and the recording medium is opposed to the ink. It has been proposed to form an image by separating and ejecting only the coloring material component from the recording liquid by forming an electric field between the recording medium and the opening in the vicinity of the recording medium.

In the image forming apparatus based on the above-mentioned flying principle, since there is no nozzle for forming flying ink unlike the conventional ink jet recording, it is possible to increase the speed by increasing the number of nozzles.

[0006]

However, the conventional ink jet recording apparatus using the ink containing the charged colorant component has the following problems.

It is desirable that the tip of the electrode for flying the colorant component is projected from the end of the substrate because the electric field strength can be increased. In the conventional ink jet recording head, an etched metal plate or the like is used as the rigidity of glass or the like. The electrode was attached to a substrate with a protrusion so that the tip of the electrode protrudes from the end of the substrate. In such a manufacturing method, the resolution is at most several tens of d.
With pi, it was only applicable to the manufacture of small scale recording heads with up to several hundred electrodes. In order to collectively manufacture recording heads having a high density, such as a resolution of 300 dpi or 600 dpi and a number of electrodes such as a line head of 2000 or more, a semiconductor processing process must be applied. However, in order to form the electrodes with high accuracy and high density in the semiconductor processing process, the tip of the electrode had to be recessed inward by several tens of microns or more from the substrate end due to the process. In the case of the recording head having such a shape, the electric field strength at the electrode tip is lowered due to the dielectric constant of the substrate, and the colorant component condensed from the electrode tip is overcome to overcome the surface tension of the solvent and fly to the counter electrode. Had to apply a fairly high voltage to the electrodes. However, if a higher voltage than necessary is applied to the electrode, the colorant component moves toward the electrode on the outer periphery of the applied electrode, and the concentration becomes high at the end. Since the ink liquid surface rises, and the distance between the raised portion and the counter electrode becomes short, an abnormal ejection phenomenon occurs in which the coloring material component jumps out from there. In addition, if the colorant component is exposed to such a strong electric field for a long time, the colorant component causes a charge transfer between itself and the electrode, and the charge disappears, so it cannot be moved by electric force. Therefore, as a result, a phenomenon in which the colorant component adheres to the electrode is caused. Furthermore, the ink meniscus at the tip of the electrode vibrates due to fluctuations in the supply pressure of the ink supplied to the substrate,
There is also a problem that it is difficult to obtain a stable ejection state.

According to the present invention, in an ink jet recording apparatus in which a coloring material component in the ink is aggregated by electrostatic force and is made to fly for recording, by lowering the flying voltage of the coloring material component, abnormal ejection is prevented and Inkjet that uses a semiconductor processing process that prevents the colorant component of the product from sticking to the electrode and also enables stable recording even when the ink pressure fluctuates, with high resolution, high integration, and high productivity. An object of the present invention is to provide a recording head manufacturing method and an inkjet recording apparatus.

[0009]

An object of the present invention is to provide an ink jet recording apparatus for recording by causing a colorant component in an ink in which a colorant is dispersed in a solvent to be aggregated by an electrostatic force and flying onto a recording medium. In an inkjet recording head used, a head substrate provided to face the recording medium, and an electrode provided on the head substrate and having a metal thin film formed on a resin protruding from an end surface thereof facing the recording medium. In an ink jet recording head including a guide member that supplies the ink adjacent to the electrodes on the head substrate, (1) a step of providing a concave groove on the first surface of the insulating substrate; ) A step of forming a first resin film on the first surface including the recess,
(3) A step of forming a metal thin film serving as an electrode on the resin film so as to project from one end surface of the groove to the groove side, (4)
A step of forming a second resin film on the metal thin film,
(5) a step of forming a metal thin film for forming the guide member on the second resin film, (6) the first resin film,
A step of processing the second resin film by dry etching,
Achieved by a manufacturing process including (7) a step of cutting the insulating substrate with the concave groove as one end surface to divide the head chip into head chips, and (8) a step of forming a third resin film on the head chip. To be done.

The first resin film is a polyimide film having a thickness of 5 to 100 μm, and the second and third resin films are
The second resin film is effectively made of polyimide having a film thickness of 0.5 to 100 μm, and the third resin film is made of polyimide having a film thickness of 0.5 to 5 μm.

The metal thin film on the electrode is made of Cu, Cr, N.
i, Al, Au, Ti, Ta, Ag, or any other alloy, and the metal thin film has a thickness of 0.5 to 10 μm.
m or the metal thin film is effectively formed by a high speed sputtering method, a vapor deposition method and an electroplating method. This is effectively achieved by the protrusion amount of the electrode from the end surface of the insulating substrate being 10 to 1000 μm.

As described above, according to the manufacturing method of the present invention, the electrode can be formed so as to project from the end face, so that the driving voltage for aggregating the colorant component and causing it to fly onto the recording medium can be lowered. Further, since the guide member is formed adjacent to the electrode, it is possible to speed up the ink supply.

Further, according to the method of manufacturing the ink jet head of the present invention, since the highly accurate semiconductor processing process is utilized, the uniformity is good and the variation is small,
It becomes easy to realize a multi-head such as a line head in which a large number of convex electrodes having the same shape are formed.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic block diagram showing an embodiment of the present invention. In FIG. 1, the insulating substrate 1 is, for example, a glass substrate or the like. On the glass substrate, an electrode 2 in which a metal thin film is formed on a resin film such as polyimide, and a guide member 3 which is also formed of a resin film such as a polyimide film are formed. The ink 6 is introduced from, for example, the ink inlet 7 in the upper part, and the ink droplets 8 are ejected from the tip of the electrode 2 exposed to the outside toward the recording medium 5 installed on the counter electrode 4. The ink 6 that is not involved in the ejection is ejected from the ink ejection port 9 and is re-injected by the circulation mechanism or the like.
Returned to.

FIG. 2 is an enlarged view showing a part of FIG. 1 in the case where a multi-head such as a line head is constructed.
A plurality of electrodes 2 are provided on the insulating substrate 1 along the main scanning direction X. In addition, as shown in FIG. 2, the tip of the electrode 2 is sharp in this embodiment. Also on both sides,
The guide member 3 is installed.

The ink used in this embodiment is 6, for example, a positively chargeable colorant dispersed in an insulating solvent having a resistance of 10 ⁸ Ω · cm or more, and is supplied from the ink inlet 7. Further, the ink 6 flows from the end portion of the insulating substrate 1 along the sub-scanning direction Y in the gap between the electrode 2 and the guide member 3 by the capillary phenomenon and reaches the tip portion.

A drive circuit 10 and a bias power supply 11 are connected to the electrode 2. The drive circuit 10 generates a signal pulse voltage with a positive polarity of, for example, 500 V, which is turned on / off in accordance with an image signal to be recorded, and this is superimposed on the bias voltage of, for example, DC 1 kV supplied from the bias power supply 11 and supplied. . That is, a voltage having the same polarity as the charging polarity of the coloring material in the ink 6 is applied to the electrode 2.
Therefore, the aggregated colorant component in the ink 6 that has reached the tip of the electrode 2 is ejected as an ink droplet 8 by electrostatic repulsion. The ejected ink droplets 8 are pulled toward the recording medium 5 arranged opposite to the recording medium 5 by the counter electrode 4 having the installation potential installed on the back surface of the recording medium 5 and fly to the recording medium 5. The image is recorded.

As described above, in the ink jet recording apparatus of this embodiment, the recording medium 5 is used in the ink jet head.
Since the tip of the head opposite to the above protrudes from the insulating substrate 1, it is possible to drive at a low voltage.

Further, since the guide member 3 is formed adjacent to the electrode 2, the ink 6 is supplied to the tip of the head by the capillarity, so that the ink layer is easily and stably formed and high performance and high quality are obtained. The inkjet recording device can be realized.

Next, a method of manufacturing the ink jet head according to this embodiment will be described. FIG. 3 shows steps of the manufacturing method of the present embodiment. Step (1) A concave groove is formed on the washed glass substrate 12 having a thickness of 1.1 mm, for example. A dicing saw was used as a method of forming the groove, the width of the groove was about 1.5 times the final protrusion amount of the electrode 2, and the depth of the groove was 200 μm.

Step (2) A polyimide film 14 as the first resin film is attached to the glass substrate 12 by laminating. As the laminating conditions, the glass substrate 12 heated to 250 ° C.
On top, a polyimide film 14 is laminated by a roll at 200 ° C. and 3 kg / cm ² . The polyimide film 14 used in this example is a film having two layers of a 15 μm polyimide layer and a 2 μm thermoplastic polyimide layer as an adhesive, and has a total thickness of 17 μm.
Polyimide film has good solvent resistance, excellent electrical insulation, and low dielectric constant, so that electrostatic force acts on the colorant component in the ink to cause ink droplets containing colorant particles to fly toward the recording medium. Therefore, it is the most suitable material for a recording head of an inkjet recording apparatus that performs recording, and also has a good dry etching property, and thus is most suitable for the manufacturing method of the present invention.

When the thin polyimide film 14 is laminated on the glass substrate 12, it is greatly deformed in the portion where the groove is formed, which hinders the electrode formation in the subsequent process. Therefore, the minimum thickness is 5 μm.

On the contrary, when a thick polyimide film 14 is laminated on the glass substrate 12, peeling easily occurs after lamination due to the difference in linear expansion coefficient between polyimide and glass, which is suitable for a long head such as a line head. I knew I couldn't. Therefore, the polyimide film 14
The thickness is preferably 5 to 100 μm, more preferably 5 to 50 μm. You may use the polyimide film which used the epoxy type and the phenol type as an adhesive agent.

Step (3) A metal thin film is formed on the glass substrate 12 by a high speed sputtering method, and the electrode 2 is formed by photoetching. In this example, the aluminum thin film 15 was formed to a thickness of 2 μm and patterned. The aluminum etchant is phosphoric acid:
An etchant having a composition of nitric acid: acetic acid: water = 16: 2: 1: 1 was used. Further, during the exposure, the alignment was performed so that the tip of the electrode 2 was projected by 200 μm with reference to the one end surface of the groove 13 on the glass substrate 12 formed in the step (1).

By forming a metal film by a high speed sputtering method, a vapor deposition method and an electroplating method, Cu, Cr, Ni, Al, Au, Ti, T
Among a, Ag, and other alloys, it is possible to freely select materials according to the purpose, such as those showing good corrosion resistance and electromigration resistance properties, inexpensive ones, and using semiconductor processing processes. As a result, it was possible to easily form a line head with high resolution and high density mounting.

The thickness of the metal film is required to be at least 0.5 μm in order to secure the adhesion to the polyimide film 14. Further, a film thickness of 5 μm or less is desirable in order to secure the resolution of patterning by the semiconductor processing process. Therefore, the thickness of the metal film is preferably 0.5 to 10 μm, more preferably 0.5 to 5 μm.

Step (4) A varnish-like polyimide b16 is applied as a second resin film on the glass substrate 12 by spin coating and curing is performed. In this embodiment, 20 cP of polyimide is used.
After spin coating at a rotation speed of 00 rpm, the final curing temperature was 350 ° C. and the film thickness was 10 μm. Polyimide b16
When spin coating is applied, the minimum film thickness is required to be 0.5 μm to prevent pinholes, and the maximum film thickness is 100 μm for the same reason as in the step (2). Therefore, the thickness of the polyimide b16 is preferably 0.5 to 100.
μm, and more preferably 1 to 50 μm. In addition, you may stick the polyimide and resin film of arbitrary thickness like a process (2).

Step (5) A metal thin film is formed on the glass substrate 12 by a sputtering method, and a guide member forming mask 17 is formed by photoetching. In the present embodiment, aluminum is formed to a thickness of 1 μm, but S having dry etching resistance is used instead of the metal thin film.
The i-based resist may be applied by spin coating.
There is no problem even if a technique such as vapor deposition or electroplating is used for forming the metal thin film.

Step (6) The polyimide film of the glass substrate 12 which has completed the step (5) is processed by dry etching using oxygen plasma. In order to process the side surfaces of the polyimide film 14 and the guide member 3 below the electrode 2 vertically, it is necessary to draw oxygen plasma from an ion source or the like and vertically irradiate the plasma to the glass substrate 12 as in the ECR type. A dry etching device that can be used is suitable. Here, the tip of the electrode 2 is formed in a state of protruding by 200 μm from one end surface of the groove 13 in the step (1).

The amount of protrusion of the electrode 2 from one end surface of the groove 13 is
At least 10 μm or more is required in terms of alignment accuracy. When the protrusion amount of the electrode 2 is 1000 μm or more, a defect such as a warp or a bend of the electrode 2 is likely to occur during the manufacturing process due to a difference in linear expansion coefficient between the metal thin film forming the electrode 2 and the polyimide film 14. Since the structural strength of is also lowered, there arises a problem that great care is required in handling after processing. Therefore, the amount of protrusion from the end surface of the electrode 2 is preferably 10 to 1000 μm, more preferably 100
To 500 μm.

Step (7) A cutting groove 18 is formed on the back side so as to be aligned with the center of the groove 13 of the glass substrate 12. Further, a cutting groove is formed to have a specified size, and finally the head chip is divided.

Step (8) A varnish-like polyimide c19 as the third resin film is applied to the divided head chip surface by spin coating to improve the ink wettability of the surface of the electrode 2 by about 1 μm on the entire surface. Cure is performed to complete the head chip substrate.

When the polyimide c19 is applied by spin coating, the minimum film thickness is required to be 0.5 μm in order to prevent pinholes, as in the case of the step (4). Polyimide c
If the film thickness of 19 is 5 μm or more, the film thickness of the polyimide c19 at the tip of the electrode 2 also becomes large, and as a result, the electric field strength at the tip of the electrode 2 also fluctuates. The drive voltage for the recording head became unstable. Therefore, the film thickness of the polyimide c19 is preferably 0.5 to 5 μm, more preferably 1 to 3 μm.

As described above, in the ink jet head according to the embodiment, the electrodes and the like are patterned by photo-etching used in the semiconductor process with the groove 13 on the glass substrate 12 as a reference, and the alignment is easy because they are formed by stacking. Therefore, it is possible to dispose electrodes with high resolution, and it is possible to realize an inkjet recording apparatus equipped with a high-performance and high-definition line head.

[0036]

As described above, according to the present invention, an electrode having a sharp tip having a metal thin film formed on a resin film and an adjacent guide member are formed so as to project from the end surface of the head substrate. Makes it possible to drive at low voltage,
In addition, it is possible to stably supply the ink.

Further, according to the method of manufacturing an ink jet recording head of the present invention, the electrodes and the guide members are aligned and patterned by using the semiconductor processing process with the groove formed on the insulating substrate as a reference, and the film is further laminated. Can be simultaneously processed by dry etching. Therefore, a line head having a large number of electrodes and a high density and a high resolution can be easily manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a main part of the inkjet head according to the embodiment.

FIG. 3 is a diagram for explaining a manufacturing process of the inkjet head according to the embodiment.

[Explanation of symbols]

1: Insulating substrate, 2: Thin film electrode, 3: Guide member,
4: counter electrode, 5: recording medium, 6: ink, 7:
Ink inlet, 8: Ink drop, 9: Ink outlet,
10: drive circuit, 11: bias power supply, 12: glass substrate, 13: groove, 14: polyimide film,
15: Aluminum thin film, 16: Polyimide film b, 1
7: Mask for forming guide member, 18: Cutting groove, 1
9: Polyimide film c.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C057 AF55 AF72 AF93 AG21 AN05                       AP11 AP32 AP52 AP54 AP55                       AP57 BD05

Claims (9)

[Claims] 1. An ink in which a colorant is dispersed in a solvent,
In an inkjet recording head used in an inkjet recording apparatus for recording by aggregating a colorant component by electrostatic force and flying it on a recording medium, a head substrate provided facing the recording medium and the head substrate. It is composed of an electrode provided with a metal thin film formed on an insulating resin protruding from the end face facing the recording medium, and a guide member for supplying the ink adjacent to the electrode on the head substrate. A method of manufacturing an inkjet recording head, comprising the step of providing a concave groove on the first surface of an insulating substrate, and the step of forming a first resin film on the first surface where the concave portion is formed, Forming a metal thin film to be an electrode on the first resin film so as to project from one end surface of the groove to the groove side; and forming a second resin film on the metal thin film. A step of forming a metal thin film for forming the guide member on the second resin film, a step of processing the first resin film and the second resin film by dry etching, and A method for manufacturing an inkjet recording head, comprising: a step of cutting a substrate by using the concave groove as one end surface to divide into a head chip; and a step of forming a third resin film on the head chip. 2. The method for manufacturing an ink jet head according to claim 1, wherein the first resin film is a polyimide film and the film thickness is 5 to 100 μm. 3. The metal thin film on the electrode is Cu, Cr,
The method of manufacturing an inkjet head according to claim 1, wherein the method is Ni, Al, Au, Ti, Ta, Ag, or any other alloy. 4. The method of manufacturing an ink jet head according to claim 3, wherein the metal thin film on the electrode is formed by a high speed sputtering method, a vapor deposition method and an electroplating method. 5. The film thickness of the metal thin film to be the electrode is 0.1.
It is 5-10 micrometers, The manufacturing method of the inkjet head of Claim 3 characterized by the above-mentioned. 6. The method according to claim 1, wherein the material of the second resin film is polyimide and the film thickness is 0.5 to 100 μm. 7. The amount of protrusion from the end face of the electrode is 10 to 1
The method for manufacturing an inkjet head according to claim 1, wherein the inkjet head has a thickness of 000 μm. 8. The thickness of the third resin film is 0.5 to 5
The method for manufacturing an inkjet head according to claim 1, wherein the inkjet head has a thickness of μm. 9. An ink jet recording apparatus equipped with an ink jet head manufactured by the method according to claim 1.